Currently, microcapsules for interior observations and microscopic operations in narrow spaces performed in the examinations of gastrointestinal tracts or the like in the medical field are proposed, for example, in Patent Documents 1 to 3.
As to a medical capsule in Patent Document 1, an inertial body is vibrated by using piezoelectric elements. A capsule body receives a frictional force between the capsule and a biological body, and the medical capsule is moved forward.
Additionally, as to an automatic traveling capsule device in Patent Document 2, it is disclosed that a capsule is moved forward by repeated energization and de-energization of a shape-memory alloy (SMA) wire, and also that a capsule is moved forward by the generation of a vibrating source for the forward and backward movements by using a coil and a permanent magnet.Moreover, as to a traveling capsule in Patent Document 3, Patent Document 3 discloses that a permanent magnet and a coil are inserted in the capsule, and an alternating current is applied to the coil for a piston movement.